There are four divisions, or "time belts," on this continent: Eastern, Central, Mountain, and Western.

The eastern time is that of the 75th meridian, the western, that of the 120th.

1. How many hours difference (Standard Time) between New York and San Francisco?

2. In traveling across the continent from San Francisco to New York, how many times would you have to set your watch to keep Standard Time?

3. In going west, would you move your watch backward or forward? In going east?

4. How many times was it necessary for the men in the New York to Paris motor car race, by way of San Francisco, to change their watches in their race around the world?

5. How many times was it necessary to change their watches in crossing the United States? Asia? Europe?

6. Were their watches set back or ahead in each case? Explain why.

REVIEW

146. Solve :

(See Tables, p. 264.)

1. How many loads in a bank of sand 6 ft. high, 20 ft. long, and 15 ft. wide?

2. How many loads in the excavation of a cellar, 25 ft. long, 16 ft. wide, and 8 ft. deep?

3. A contractor received 75 cents a load for excavating a cut for a road, 116 ft. long, 20 ft. wide, and averaging 15 ft. deep. How much did he receive?

is constructed of timber, 3 in. by 4 in., each stick used being 10 ft. or 16 ft. long and used with the least waste. The rafters are 2 ft. apart. The joists, represented by the dotted lines, are also 2 ft. apart all around the main part of the building.

4. How many sticks of timber, 16 ft. long, must be used in building this garage? How many sticks of timber, 10 ft. long, can be used?

5. Allowing three 16-ft. sticks of timber for the gable ends, how many feet of timber were used? What is it worth at 3 cts. per running foot?

* In measuring excavations the unit is 1 cubic yard, which is called a load.

6. Making no allowance for windows, doors, or waste, how many square feet of boards would it take to cover the main part of the building? How many square feet in the gable?

7. How many square feet in the roof? What would the boards to cover the sides and ends of the building cost at $40 per M?

8. (Shingles are laid 4 in. to the weather and a shingle is 4 in. wide. Each shingle covers 16 sq. in., or there are 9 shingles to a square foot.) How many shingles did it take to shingle the roof? What would they cost at $8 per M?

9. Allowing $7.50 for extra work on the doors, and $5 for the windows, and 12 days' carpenter work, at $4.80 a day, what was the cost of the building ?

10. The survey for a new road made the length 312 chains, 75 links. How long was it in miles, rods, and feet? In miles and decimals of a mile?

11. It is 12 miles and 3 rods from the post office of Amity to that of Coleville. How many chains and links?

12. The steamship Adriatic draws 22 ft. of water. How many fathoms deep must the water be for her to sail in? 13. How many in a pound? In an ?

14. How many 3 in 1 lb.?

15. Write as decimals of a pound, 33 43 50 D.

16. A gold dollar weighs 25.8 grains. What is the weight of a gold eagle? Of $1,000,000 of gold?

17. A silver dollar weighs 412.5 grains. What is the weight of $1,000 in silver?

18. If you are worth your weight in silver, how many dollars are you worth? (Reduce to grains. Why?)

19. The longitude of Berlin, Germany, is 13° 23′ 43.5′′ E. That of Dublin, Ireland, is 6° 20' 30" W. When it is 7 A.M. at Dublin, what time is it at Berlin?

20. A man bought a plot of land in the form of a trapezoid. The length of one side was 256 ft., and that of the other side parallel to it was 328 ft. The distance between the parallel sides was 110 ft. How many acres did the plot

contain?

21. Find the difference in area between a rectangle 36 ft. long and 24 ft. wide, and a trapezoid whose parallel sides measure 30 ft. and 42 ft. respectively, the distance between the parallel sides being 24 ft.

22. Classify the following units of measurement, making 3 groups of them. In Group One place all that refer to linear measurement, in Group Two all that refer to area, and in Group Three all that refer to volume.

Acre, inch, square foot, cord foot, mile, yard, section, cubic yard, rod, cubic foot, perch, square, square inch, square mile, square yard, link, chain.

23. Draw a rectangle; a square; a circle; a right triangle; a trapezoid.

24. There are two fields, each of which has a perimeter of 180 rd. One of them is a square, and the other a rectangle 8 times as long as it is wide. Which is the larger field?

25. What is the length of the rectangular field?

SUMMARY OF CHAPTER III

DENOMINATE NUMBERS

Reduction.

The Fundamental Processes.

APPLICATIONS OF DENOMINATE NUMBERS.

Measurements.

Longitude and Time.

CHAPTER IV

PERCENTAGE-APPLICATIONS OF PERCENTAGE

FINDING PERCENTAGE

1

100°

It is

147. 1 Per cent means 1 in each hundred, or written 1% or .01. Per cent (centum) means by the hundred.

Of what per cent is each of the following common fractions the equivalent :

1, 1, 1, 1, 1, 1, 16, 12, 16?

Write each as a decimal.

In decimals, one tenth is the unit of calculation; in percentage one hundredth is the unit, but the decimal notation is used.

The terms of percentage are base, rate, percentage, amount, and difference.

The base is the quantity on which the percentage is reckoned.

The rate is the stated number of hundredths of the base. It is read "per cent."

The percentage is the number of hundredths of base by the rate.

quantity that equals the stated e base. It is the product of the

The amount is the sum
The difference is the ba
The amount is represented by 100% + the rate.
The difference is represented by 100% the rate.

the base and the percentage.
less the percentage.

87